Re: Physical replication slot advance is not persistent
Kyotaro Horiguchi <horikyota.ntt@gmail.com>
From: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
To: michael@paquier.xyz
Cc: a.kondratov@postgrespro.ru, craig@2ndquadrant.com, andres@anarazel.de,
pgsql-hackers@postgresql.org, simon@2ndquadrant.com
Date: 2020-01-29T08:10:20Z
Lists: pgsql-hackers
At Wed, 29 Jan 2020 15:45:56 +0900, Michael Paquier <michael@paquier.xyz> wrote in > On Tue, Jan 28, 2020 at 06:06:06PM +0300, Alexey Kondratov wrote: > > On 28.01.2020 15:14, Kyotaro Horiguchi wrote: > >> But the doc part looks a bit too detailed to me. Couldn't we explain > >> that without the word 'dirty'? .. > >> and it will not be moved beyond the current insert location. Returns > >> name of the slot and real position to which it was advanced to. The > >> information of the updated slot is scheduled to be written out at the > >> follow-up checkpoint if any advancing is done. In the event of a > >> crash, the slot may return to an earlier position. > > > > Just searched through the *.sgml files, we already use terms 'dirty' and > > 'flush' applied to writing out pages during checkpoints. Here we are trying > > to describe the very similar process, but in relation to replication slots, > > so it looks fine for me. In the same time, the term 'schedule' is used for > > VACUUM, constraint check or checkpoint itself. > > Honestly, I was a bit on the fence for the term "dirty" when typing > this paragraph, so I kind of agree with Horiguchi-san's point that it > could be confusing when applied to replication slots, because there is > no other reference in the docs about the link between the two > concepts. So, I would go for a more simplified sentence for the first > part, keeping the second sentence intact: > "The information of the updated slot is written out at the follow-up > checkpoint if any advancing is done. In the event of a crash, the > slot may return to an earlier position." Looks perfect. regards. -- Kyotaro Horiguchi NTT Open Source Software Center
Commits
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Fix oldest xmin and LSN computation across repslots after advancing
- 1657e14b50d2 11.9 landed
- 16f43122d46f 12.4 landed
- 43e70addf5a6 13.0 landed
- b48df818dcbd 14.0 landed
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Fix slot data persistency when advancing physical replication slots
- 374464c3e96f 11.7 landed
- 3228512b7b2b 12.2 landed
- b0afdcad21fd 13.0 landed